Sydney 2005: What is the Role of Reduced Intensity Allogeneic Stem Cell Transplantation?

By Francis Ayuk, MD

04.13.05

Dr. Ayuk presented results of studies looking at allogeneic stem cell transplant (allo-sct) for MM conducted in the EU. The strategy used was to offer dose reduced melphalan-fludarabin in newly diagnosed MM patients. The treatment strategy was successful, with a low rate of treatment related mortality (18%) and good responses (CR=49%, PR=38%). At 2 years, OS was 59% and progression free survival (PFS) was 39%; relapse at 2 years was 43%. Notably, OS after allografting was better in patients who had not relapsed. Data suggest that auto-allogeneic tandem transplant strategy is a more promising strategy than a salvage strategy. In another trial, patients completed autologous and allogeneic transplantations. Stem cells were the source of cells in more than 90% of the cases and 124 days separated the transplants. Following allogeneic transplant, 6% of patients were in complete response (CR), 37% in partial response (PR), 2% in minor response (MR). After allograft, 55% were in CR, 27% in PR, and 3% had progressive disease. Acute graft versus host disease (GVHD) was seen in 42% of patients; mortality was 7% at 1 year. At 4 years post transplant, OS was 68%. Notably, related and unrelated donors showed no difference in disease free survival. In summary, the data suggest that transplantations should be performed at early stages of disease, that donor lymphocyte infusions (DLI) is effective in relapsed patients, and that thalidomide used in DLI enhances remission rates without occurrence of severe GVHD. Looking forward, dose reduced allografts should be a part of broad treatment strategies which includes autologous transplantation, DLI, and emerging drugs.